Joint connection for sheet-metal units



Sept. 24, 1929. A. R. GROSS 1,728,964

JOINT CONNECTION FOR SHEET METAL UNITS Filed July 2, 1928 the shell, only one of which is s Patented Sept. 24, 1929 UNITED STATES PATENT OFFICE I ARTHUR R. GROSS, OF ST. PAUL, MINNESOTA, ASSIGNOR TO GROSS METAL PRODUCTS COMPANY, OF ST. PAUL, MINNESOTA, A CORPORATION OF MINNESOTA I JOINT CONNECTION FOR SHEET-METAL UNITS Application filed July 2, 1928. Serial No. 289,734.

My present invention relates to the construction of a sheet metal unit or shell including a pair of laterally spaced plates and more particularly a method of connecting 5 the plates, which includes two series of cooperating lock elements arranged to be interlocked the one with the other by a relatively slight movement of one of the plates in respect to the other to rigidly connect said two plates.

The invention, while intended for general use is especially well adapted for use in the construction of a hollow sheet metal door.

To the above end, generally stated, the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claims.

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings: Fig. 1 is a fragmentary vlew in transverse section showlng a hollow sheet metal shell in which the invention is embodied;

:10 separated the one from the other.

The shell illustrated in the drawings cornprises a pair of laterally spaced sheet metal plates 5 and 6 and a truss structure 7 within structure 7 is first welded to one of the plates the shell and rigidly connecting said plates.

I Said truss structure 7 comprises a corrugated sheet metal plate having flat apexes 8 that alternately and directly engage the inner faces of the plates 5 and 6 and are rigidly and permanently secured thereto by spot welding, as indicated at 9.

The two plates 5 and 6 at their longitudinal edge portions are bent laterally toward each other in substantially the same plane to form the longitudinal edge portions of own. The

edge-forming section of the plate 5 is relatively wide and indicated by the numeral 10 and the edge-forming portion of the plate 6 is relatively narrow and indicated by the numeral 11.

By reference to Fig. 1 it will be noted that the edge-forming sections 10 and 11 have abutting engagement at their longitudinal edges andform a smooth and relatively tight joint 12 therebetween. The edge section 10 is laterally and inwardly" extended at 13 and has integrally formed therewith a series of laterally projecting hook-equipped lugs 14 which overlap the inner face of the edge section 11 and have direct contact therewith, as shown in Fig. 1. A second series of hook-equipped lugs 15 of the same shape as the lugs 14 are integrally formed with the longitudinal edge portion of said section, but in reverse arrangement to the lugs 14 as shown in Figs. 3 and 4.

It is important to note that the longitudi-- nal spacing of the lugs 14 and 15 of the two series is such as to permit the lugs of one series to beinserted between the lugs of the other series, thus permitting the lugs of one series to be inserted between the lugs of the other series by a slight lateral movement of one of the plates 5 and 6 in respect to the other and then interlocked with said other lugs by a slight longitudinal movement of said plate in respect to the other.

In the construction of the shell, the truss 56 and then the two plates are assembled by a compound lateral and edgewise movement of one of the plates in respect to the other to cause one series of the lugs 1415 to interlock with the other and thereafter the truss structure 7 is welded to the other plate.- With the truss structure 7 welded to both plates said plates are rigidly held connected and the lugs 14 and 15 are likewise securely held interlocked so as to form a tight and rigid joint connection between the two edge sections 10, and 11 of the shell.

Obviously; the interlocked lugs 14 and 15 of the two series securely hold the two edge sections 10 and 11 rigidly connected against movements in all directions except to separate said lugs and this movement is prevented by the connection of the plates 5 and 6 by the truss 7. It will be noted that the lugs 1415 have rounded or tapered corners 16 which permit the sameto be readily interlocked the one with the other during the assembling of the plates 5 and 6 to form the shell.

What I claim is:

1. A pair of plates and two series of cooperating lock elements connecting the same, one of said plates having a lateral extension, the lock elements of one series being on said extension and extending laterally therefrom parallel to the respective plate, the lock elements of the other series being on the other plate, overlapping said extension and extending transversely of the lock elements thereon.

2. The structure defined in claim 1 in which the plates are rigidly connected and hold the two series of lock elements interlocked.

; lugs connecting the same, one of sai 3. The structure defined in claim 1 in which at least the lock elements of one of said series are in the form of hook-equipped lugs.

4. The structure defined in claim 1 in which the longitudinal spacing of the lock elements of each series being such as to permit the lock elements of one series to pass between the lock elements of the other series and be interlocked the one series with the other by acompound lateral and longitudinal movement of one of the plates in respect to the other.

5. A pair of plates having lateral extensions in the same plane and two series of cooperating lock elements connecting the same, the lock elements of one series being on one of the lateral extensions and extending laterally therefrom parallel to the respective late, the lock elements of the other series ing on other lateral extension, laterally oifset therefrom, overlapping the first noted lateral extension and extending transversely of the lock elements thereon.

6. A pairof locked reverse y extending hook-eguipped plates having a lateral extension, one series of said lugs being on the lateral extension and projecting laterally therefrom parallel to the re- I spective plate, the other series of said lugs being on the other plate and extending parplates and two series of inter- In testimony whereof I aflix my signature.

ARTHUR R. GROSS. 

